Image producing devices such as kaleidoscopes are well known in the art. Kaleidoscopes are all basically similar in that they have an eyepiece at one end of a hollow tube, longitudinally extending planar mirrors angularly disposed within the tube, and an object case at the other end of the tube. The objects are usually colorful, of a wide variety of shapes, and transparent, although they are sometimes translucent and, less frequently, opaque. Generally, the eyepiece, the viewing end, is opaque with a transparent hole or viewing means while the outward facing end of the object case, the light receiving end, is translucent. The objects within the object case are illuminated by aiming the device at a source of light such as a lamp or bright window. Many variations and refinements of this basic device have been developed, including the expedient of suspending the objects in a clear liquid medium and the provision of self-contained illumination sources. The devices described in U.S. Pat. No. 3,383,150 issued to E. A. Powers are typical.
Also known in the art are image producing devices characterized by a tube having an arcuate internal reflecting surface rather than angularly related planar mirrors. Like kaleidoscopes, these devices may contain a plurality of objects of varying size, color and shape within a light transmitting object enclosure.
It has also been proposed that such devices contain two polarizing sheets having birefringent material therebetween. The two polarizers are fixed to two tubular parts which are mounted for relative rotation. Rotation of the tubular parts results in rotation of the polarizing sheets which in turn causes the color of the light transmitted through the birefringent material to change. One such device is disclosed in U.S. Pat. No. 3,841,730 which is incorporated herein by reference. Such a prior art device is expensive to produce being very labor intensive.